In order to allow a medical instrument brought into the surgical area by way of the working channel to be directed accurately to the area of application, a known method is to configure the part of the working channel situated in the endoscope head so that it can be rotated with respect to the related working channel by means of a Bowden cable. In the endoscope introduced in EP 1 112 019 B1, the Bowden cable serving to rotate the working channel is mounted on the proximal end by means of a collet mounted on a control handle. By means of the collet, the cable cord of the Bowden cable is grasped by clamping and is held clamped in the collet according to the depth of insertion.
This known construction for clamping the Bowden cable has the disadvantage that the cable cord can be inserted so deep in the collet that the cable cord becomes too taut and it becomes scarcely possible to rotate the working channel. To minimize this danger, the working channel and thus the cable cord of the Bowden cable must first be moved into a predetermined starting position so that thereafter a sufficient but not too taut tightening of the cable cord by the collet is possible. This known clamping method is, on the one hand, complicated and, on the other hand, does not prevent faulty tightening of the cable cord.
On this basis, it is the object of the invention to produce an endoscope of the aforementioned type in such a way that a constantly even tension of the Bowden cable is ensured, along with simple construction.